Deficiency of essential vitamins and minerals leads to various symptoms and diseases. - Iron deficiency is the most common cause of Anaemia (ii), a condition characterized by a reduced number of red blood cells. - Iodine deficiency affects thyroid function and is a major cause of preventable mental disability, particularly cretinism in children (iii). - Calcium is vital for bone and teeth health. Deficiency can lead to weakened bones (osteoporosis) and contribute to dental problems including tooth decay (iv), as teeth structure relies on calcium. - Vitamin B1 (Thiamine) deficiency causes Beriberi, symptoms of which include weakness, fatigue, nerve damage, and muscle weakness (i).